Dental impression composition



Reissues! Aug. 18, 1953 sum pmsr. mrrmssr'on ooMrosrrroN Edwin II.Lochridge, Glendale, alif., assignor to Dental Perfection Company, a

California company of No Drawing. Original No. 2,568,752, datedSeptember 25, 1951, SeriaLNo. 764,247, July 28, 1947. Application forreissue January 21, 1953,

Serial No. 332,581

zs Claims. (oi. 1 7) Matter enclosed in heavy brackets I: appears in theoriginal patent but forms no part of this relaauo specification; matterprinted in italics indicates the additions made by reissue.

1 This invention relates to a new dental impression compound and themethod of producing the same.

For many dental purposes such as making of full dentures, partialdentures, bridges, etc., it is necessary for the dentist to be able toaccurately reproduce portions of the mouth of the subject. Suchreproductions often involve the duplication of undercuts of more or lessseverity, as for instance in the case where a tooth or teeth have beenextracted and the adjacent teeth have crowded together.

l'br many years dental impressions have been taken with materials suchas plaster of Paris, or various shellac or wax compositions. Thesematerials have little or no elasticity and while it is not difficult .totake some impressions with them, such as for most full dentures, it isnot possible to reproduce accurately undercuts without either breakingthe impression and re-assembling it, as is done with plaster, or takingthe impression in sections, as is the practice in the use of shellac andwax compounds. The foregoing methods obviously involve time and there isthe danger-of inaccuracy, as well as discomfort to the patient.

My dental impression material is composed of a suitable gel formingagent, such as sodium, potassium or ammonium alginate, sodiummethylcarboxycellulose or sodium, potassium or amnionium pectate.Mixtures of the foregoing gel forming agents may be used in my newcomposition.

To the above gel forming agent there is added lead monosilicate. I havefound that lead monosilicate is especially desirable in my compositionsince it eliminates the necessity of a setting agent, such as calciumsulphate. All forms of lead silicate do not give satisfactory results inmy composition. For example, I have found that lead bisilicate will notproduce a satisfactory impression material when used in my composition.The difference in behavior of lead monosillcate and lead bisilicate willbe apparent by reference to the examples in the specification.

. To the above composition I also add a fluosilicate. Most fluosilicatesappear to give satisfactory results, however, I prefer to use sodiumfluosilicate, aluminum iluos'ilicate and ammonium fluosilicate.

To the foregoing compounds I also add a filler, such as diatomaceousearth in a finely ground form. Other fillers, such as fullers earth ortalc may also be used.

I also add an alkali metal carbonate, such as sodium or potassiumcarbonate. Or in place of the carbonate I may add a water solublephosphate.- Many phosphates work satisfactorily, for example, I may usetrisodium phosphate, sodium metaphosphate, potassium diphosphate,primary sodium phosphateor sodium acid pyrophosphate, however, I findthat tetrasodium pyrophos'phate works especially well. In using any ofthe foregoing phosphates or carbonates in my composition caution must beexercised in the amount employed since the final composition is verysensitive to a change in the amount of these ingredients employed. Theuse of either too much phosphate or carbonate tends to retard or inhibitthe set in the final composition.

To the foregoing I add sumcient water to form a stiff paste whenspatulated (mixed) and then place this paste into the dental tray fortaking the impression.

It is, therefore, an object of the present invention to produce acomposition of matter suitable methyl carboxycellulose, an alkali metalcarbonate or a phosphate and water.

The following compositions are modifications ofthe impression materialmade according to my invention. These composition were blended byrollingin a small :Iar mill:

Example I Grams Material Diatomaoeous earth. Exfoliated Peal-lite (210mesh). Lead monosllicate.

Potauium alginate. Tetrasodium pyrophosphate. Sodium fluosiiicate.

sta es Sixteen grams of the foregoing blended com- .position werethoroughly mixed with 25 cubic centimeters of water (70 F.) in a rubbermixing vessel with a spatula, after which the contents of the mixingvessel were transferred to the sur- Sixteen grams of the foregoingcomposition were mixed, as in Example I, with 25 cubic centimeters ofwater (at 70 F.) and placed on a glazed tile. After 3 minutes themixturegplaced on the tile had become firmly set.

Example In eassjs Thirty-two grams of the above blend were mixed with 50cubic centimeters of water (at 70 F.) and the mixture was transferred toa glazed tile. After 2% minutes this mixture placed on the tile hadbecome firmly set.

Example IV The following basic blend was mixed inasmall Jar mill:

Grams Material 4. 5 Diatomaoeous earth. 0. 9 Potassium alginate. 3.;8122mm slglnate. b In. rasodium pyro osp l. 25 Aluminum fluosili c ats.

(A) 5 grams of lead monosilicate were added to 7.35 grams of the abovebasic blend and the resultant mixture was spatulated with 25 cubiccentimeters of water (at'70 F.) This spatulated mixture when placed upona glazed tile produced a good set at the end of six minutes.

(B) 4 grams of lead monosilicate were added to 7.35 grams of the abovebasic blend and the resultant mixture was spatulated with 25 cubiccentimeters of water (at 70 F). This-spatulated mixture when placed upona glazedtile produced a good set after six minutes.

(C) 3 grams of lead monosilicate were added to 7.35 grams of theabovebasic blend and the resultant mixture was spatulated with 25 cubiccentimeters of water (at 70 F.) This spatulated mixture was placed upona glazed tile and a fair set was obtained in six minutes.

.(D) 2 grams of lead monosilicate were added to 7.35 grams of the abovebasic blend and the resultant mixture was spatulated with 25 cubiccentimeters of water (at 70 F.). The spatulated mixture was placed upona glazed'tile andafter minutes this composition was only slightly setand had a very poor texture.

(E) 5, 10 and 20 grams, respectively, of lead bisilicate were added tothree 7.35 gram portions of the above basic mixture. 25 cubiccentimeters of water were added to each mixture and after spatulationeach resulting composition was placed on a separate glazed tile. Afterremaining minutes on the tile none of these spatulated compositions hadset. Each composition was still in the form of a mush or paste.

Example V The following basic blend was mixed in a small jar mill:

Grams Material 4.50 Diatomsceous earth. 011 Potmum algina g :3 new h h uum p a 0.75 Sodium fiuoslfia s. mp

(A) 5 grams of lead monosilicate were added to 6.85 grams of the abovebasic blend and the resultant mixture was spatulated with 25' cubiccentimeters of water (at 70 F.) The spatulated mixture was placed upon aglazed tile and 2% minutes after spatulation had produced a good set.

(B) 4 grams of lead monosilicate were added to 6.85 grams of the abovebasic blend and the resultant mixture was spatulated with 25 cubiccentimeters of water (at 70 F.-). The spatulated mixture when placedupon a glazed tile produced a good set in six minutes.

with 6.85 grams of the above basic blend and 25 cubic centimeters ofwater (at 70 F.) were a the constituents in a small jar then added.After spatulation this mixture was placed upon a glazed tile andproduced a fair set after six minutes.

(D) 2 grams of lead monosilicate were mixed with 6.85 grams or the abovebasic blend, 25 cubic centimeters of water (at 70 F.) were added andafter spatulation (mixing) this mixture was placed upon a glazed tile.After a period of 20 minutes this composition was very fragile.

(E) 20 grams of lead bisilicate were added to 6.85 grams of theforegoing basic blend, 25 cubic centimeters of water (at 70 F.) wereadded and the mixture thoroughly spatulated. After twenty minutes fromthe time of spatulation the composition was still mushy.

Example VI The following basic blend was made by rolling mill.

Grams Material Diatomaoeous earth. fiw i 'h 1..

e um yro as to. Sodium fluosificat p (A) 5 grams of lead monosilicatewere mixed with 7.5 grams of the above basic blend, 25 cubic centimetersof water (at 70 F.) were added and the mixture thoroughly spatulated.The spatu- (C) 3 grams of lead monosilicate were mixed Ilatedmixtureproducedagoodsetinthreeand one-half minutes. I

(B) The foregoing experiment (Example VI (A))wasrepeatedusin'g4,3and2grams.respectively, in three separate 7.5 gramportions of the basic blend with cubic centimeters of waterhadaverymushyconsistencyaftertenminutes.

(C) The foregoing experiment (Example VI (A)) was substituting 20 gramsof lead .bisilicate in place of the 5 grams of lead monosillcate. Thefinal composition was still mushy and unsatisfactory minutes afterspatulation.

Example VII The following blend was made by mixing theconstituentsinasmailjarmill:

mural Dlatomaceous earth.

Aluminum fiifo i l ate.

Lead monosilicnte.

. The above mixture was spatulated with 25 cubic centimeters of water(at '10 F.) and after three minutes produced a very satisfactory set.

Example VIII The following basic formula was made by mixing theingredients in a small jar mill:

Grams Material Diatomaoeous earth.

Sodium alginate glow viscosity). Sodium alginate medicinal purity).Tetrasodiom pyrophosphate. Aluminum fluosilicate.

(A) 5.0 grams of lead monosilicate were mixed with 7.1 grams of theabove basic blend together 25 cubic centimeters of water (at 70 F).

Six minutes after mixing this composition produced a good set.

(B) The foregoing experiment (Example VIII (A)) .was repeated using 4, 3and 2 gram por-.

tions of lead monosiiicate, respectively with three separate 7.1 gramportions of the basic blend and with 25 cubic centimeters of water (atcubic centimeters of water (at 'm". a). After nrteen minutes thiscomposition had produced a weak set and was unsatisfactory.

Example IX The following basic blend was made by mixing the constituentsin a small Jar mill:

'Ietrasodium hos hate Sodium flnosl m p (A) 5 grams of lead monoulicatewere mixed with 6.85 grams of the above basic blend and with 25 cubiccentimeters of water (at 70" E). After six minutes'this compositionproduced a good set.

(B) The above experiment (Example IX (A)) was repeated using 4 grams oflead monosilicate.

minutes.

(C) The above experiment (Example IX (Al) was repeated using 3 grams oflead monosilicate. This composition produced a fair set in six minutes.

(D) The above experiment (Example IX (A)) was repeated using 2 grams oflead monosilicate. An unsatisfactory set was obtained at the end oftwenty minutes.

(E) The above experiment (Example IX (Al) was repeated using 10 gramsoflead monosilicate. A very good set was obtained in three minutes.

(F) The above experiment (Example IX (A)) was repeated using 20 grams oflead monosilicate.

A good set was obtained in about three to four minutes.

(G) The above experiment (Example IX(A)) was repeated using 20 grams oflead bisilicate in place of the lead monosilicate. After thirty minutesthis composition was still mushy and had not set.

Example X The following basic blend was mixed in a small jar mill:

Grams Material :3 Ammoni alginate um 65 0.21 Tetrasodi v o. 1. m'sssa(A) 5 grams of lead monosilicate were mixed with 7.25 grams of the abovebasic blend together with 25 cubic centimeters of water (at 70 F.). Thiscomposition produced a good set in one and one-half minutes aftermixing.

(B) The above experiment (Example X (A)) was repeated using 4 grams oflead monosilicate. This composition produced a good set in two andone-half minutes after mixing.

' (C) The above experiment (Example X (A)) 70 was repeated using 3 gramsof lead monosilicate.

This composition was very fragile after six minutes from time of mixingthe final composition.

(D) The above experiment (Example X (A)) was repeated using 2 grams oflead monosilicate.

7 After standing for twenty minutes from the time This compositionproduced a good set in six The following basic blend was made in a smalljar mill:

Grams Material 4. 50 Diatomaeeous 1% T tree s di l iospliata e umyrop 1. 25 Aluminum m oaillcate.

(A) '5 grams of lead monosiiicate were mixed with 7.75 grams of theabove basic blend and with 25 cubic centimeters of water (at 70 FL).This composition produced a good set in two minutes.

(B) The above experiment (XI (A)) was repeated using 4 grams of leadmonosilicate. This composition produced a good set in two and onehalfminutes.

(C) The above experiment (In (A)) was repeated'using 3 grams of leadmonosilicate. This composition was mushy and fragile after ten minutesfrom the time of mixing.

(D) The above experiment (Xi (A)) was repeated using 2 grams of leadmonosilicate. After standing twenty minutes this composition was verymushy and unsatisfactory.

(E) Th above experiment (XI (A)) was repeated using 20 grams of leadbisilicate in place of the lead monosilicate. This composition was mushyafter standing twenty minutes.

(A) 0.2 gram sodium carbonate (anhydrous) was mixed with 11.5 grams ofthe foregoing basic blend and with 25 cubic centimeters of water (at 70F.). This composition produced a good set in three minutes.

(B) The above experiment (Example HI (A)) was repeated in which thesodium carbonate was replaced with 0.2 gram trisodium phosphate. Thiscomposition produced a good set in three minutes.

(C) The above experiment (Example XII (A)) 25 cubic centimeters of water(at 70 F.).

8 Example XIII The following composition was blended:

Grams Material Diatomaoeous earth.

Lead monosilicate. 4

Sodium alginate (low viscosity). Sodium alglnate (medicinal purity).

Sodium iluosillcate.

To the above mixture there was added .05 gram primary sodium phosphateand 25 cubic centimeters of water and this composition was thenthoroughly mixed. This composition produced a good set in two minutes.

0 Example XIV I The following basic blend was obtained b mixing in asmall jar mill:

Grams Material 00 Diatomaeeous earth 200 Lead monosilicate 40 Pectinmethoxyl.

4 Tetrasodium pyrophosphate.

(A) 19.5 of the above basic blend was mixed with .350 gram of aluminumfiuosilicate and 25 cubic centimeters of water (at 70 F.) Thiscomposition produced a good set in six minutes.

(B) 21 grams of the above basic blend was mixed with 0.250 gram ofsodium fiuosilicate and This composition produced a good set in fiveminutes.

Example XV The following ingredients were mixed together:

was repeated in which the sodium carbonate was replaced by 0.2 gram ofsodium meta phosphate. This composition produced a good set in twominuta.

(D) The above experiment (Example XII (A)) was repeated using 0.1 grampotassium diphosphate in place of the sodium carbonate. This compositionproduced a fair set in twenty minutes.

Material Diatomaceous earth.

Lead monosilicate. Potassium alginate. Sodium alginate (medicinalpurity). Tetrasodium pyrophosphate. Sodium carboxymethyl cellulose.Aluminum iluo silicate.

The above basic blend was mixed with 25 cubic centimeters of water (at70 F.) This composition produced a good set in seven minutes.

Example XVI The following basic blend was mixed in a small jar mill:

Grams Material 40.0 Diatomaceous earth. 150. 0 Lead monosilicate.

l0. 0 Sodium carhoxymethyl cellulose.

. 9' ExamplexVII The 'iollowing basic blend was made in a small jarmill: 4

Grams Material 90. Diatomaceous earth. 200 Lead monosilicate.

18 Potassium alginate; Sodium alginatc (medicinal purity).

4 Tetrasodium s1gyrophosphate. 10 Sodium fluo 'cate.

34 grams of the above composition were mixed with 50 cubic centimetersof water (at 10 F.). This composition produced a very satisfacto y setin two and one-half minutes when placed upon a glazed tile.

To clarify what is meant by the term setting time in Examples I to XVII,inclusive, all of the compositions with the added water were mixed orspatulated in a flexible rubber cup with an ordinary steel spatula,after which the contents of the cup were placed upon a glazed tile. Thetimes shown in the foregoing examples are taken from the time the wateris added to the composition and start of spatulation.

In addition to using lead monosilicate I may also use lead disilicate.Both of these compounds are orthosilicates. Lead bisilicate is themetasilicate and, as stated above, is unsatisfactory in my composition.

I claim:

1. [A] An impression composition [of matter comprising] convertible bymixing with water to an elastic gel consisting essentially of an alkalimetal alginate, [salt of a weak organic acid selected from the groupconsisting of pectic, alginic, and methylcarboxycellulose acids,] sodiumfluosilicate and lead orthosilicate.

2. [A] An impression composition [of matter comprising] convertible bymixing with water to an elastic gel consisting essentially of an alkalimetal alginate, sodium fiuosilicate, lead orthosilicate and an alkalimetal phosphate.

3. [A] An impression composition [of matter comprising] convertible bymixing with water to an elastic gel consisting essentially of an alkalimetal alginate, sodium fluosilicate, lead orthosilicate and an alkalimetal carbonate.

4. [A] An impression composition [of matter comprising] convertible bymixing with water to an elastic gel consisting essentially of an alkalimetal alginate, [salt of a weak organic acid selected from the groupconsisting of pectic, alginic and methylcarboxycellulose acids,] afluosillcate, lead monosilicate and an alkali metal phosphate.

5. [A] An impression composition [of matter comprising] convertible bymixing with water to an elastic gel consisting essentially of an alkalimetal alginate, sodium fluosilicate,- lead monosilicate, an alkali metalpyrophosphate and a filler.

6. [A] An impression composition [of matter comprising] convertible bymixing with water to an elastic gel consisting essentially of an alkalimetal alginate, [salt 0! a weak organic acid selected from the groupconsisting of pectic, alginic and methylcarboxycellulose acids,] afluosilicate, lead disilicate, an alkali metal carbonate and a filler.

'l. [A] An impression composition [of matter comprising] convertible bymixing with water to an elastic gel consisting essentially of an alkalil0 ,1 metal alginate, sodium fluosilicate. lead disilicate, an alkalimetal phosphate and a filler.

8. [A] An impressioncomposition [of matter comprising] convertible bymixing with water to an elastic gel consisting essentially of an alkalimetal alginate, sodium fluosilicate, lead disilicate, an alkali metalpyrophosphate and a filler.

9. [A] An impression composition [of matter comprising] convertible bymixing with water to an elastic gel consisting essentially of an alkalimetal alginate, sodium fluosilicate, at least 34.1% oi leadmonosilicate, an alkali metal pyrophosphate, and a filler.

10. [A] An impression composition [of matter comprising] convertible bymixing withwater to an elastic'gel consisting essentially of an alkalimetal alginate, sodium fluosilicate, at least 34.1% of leadmonosilicate, an alkali metal carbonate and a filler.

11. [A] An. impression composition [0! matter comprising] convertible bymixing with water to an elastic gel consisting essentially of an alkalimetal alginate, [salt of a weak organic acid selected from the groupconsisting of pectic, al-

ginlc and methylcarboxycellulose acids,] as fluosilicate, leadmonosilicate, .a filler, and an ala kali metal carbonate.

12. [A] An impression composition [of matter comprising] convertible bymixing with water to an elastic gel consisting essentially of an alkalimetal alginate, [salt of a weak organic acid selected from the groupconsisting of pectic, alginic and methylcarboxycellulose acids,]a-fluosilicate, lead disilicate, a filler and an alkali metal phosphate.

13. [A] An impression composition [0! matter comprising] convertible bymixing with water to an elastic gel consisting essentially of an alkalimetal alginate, sodium fluosilicate, lead monosilicate, an alkali metalphosphate and a filler in which composition the ratio of sodiumfluosilicate to lead monosilicate is between 1 to 3 and 1 to 20.

14. [A] An impression composition [of matter comprising] convertible bymixing with water to an elastic gel consisting essentially of an alkalimetal alginate, sodium fluosilicate, lead monosilicate, an alkali metalcarbonate and a filler in which the ratio 01 sodium fluosilicate to leadmonosilicate is between 1 to 3 and 1 to 20.

15. [A] An impression composition [oi matter] as claimed in claim 4 inwhich the fluosilicate is aluminum fluosilicate.

16. [A] An impression composition [of matter] as claimed in claim 6 inwhich the fluosilicate is aluminum fluosilicate.

17. [A] An impression composition [of.mat-

ter] as claimed in claim 11 in which the fluo silicate is aluminumfluosilicate.

18. [A] An impression composition [oi matter] as claimed in claim 12 inwhich the fluosilicate is aluminum fluosilicate.

19. An impression composition convertible by mixing with water ,to anelastic gel comprising an alkali metal salt of pectic acid, sodiumfluosilicate and lead orthosilicate.

20. An impression composition convertible by mixing with water to anelastic gel comprising an alkali metal salt of pectic acid, afluosilicate, lead monosilicate and an alkali metal phosphate.

21. An impression composition convertible by mixing with water to anelastic gel comprising an alkali metal salt of pectic acid, afiuosilicate, Leg: disilicate, an alkali metal carbonate and a 22. Animpression composition convertible by mixing with water to an elasticgel comprising an alkali metal salt of pectic acid, a fluosilicate, leadmonosilic'ate, a filler and an alkali metal carbonate.

.23. An impression composition convertible by mixing with water to anelastic gel comprising an alkali metal salt of pectic acid, afiuosilicate, lead disilicate, .a filler and an-alkali metal phosphate24. An impression composition convertible by mixing with water to anelastic gel comprising an alkali metal salt of methplcarboavcellulose,

' sodium flaosilicate and lead orthosilicate.

25. An impression composition convertible by mixing with water to anelastic gel comprising an alkali metal salt of methglcarbortgeellulose,a fluos'ilicate, lead monosilicate and an alkali metal phosphate.

.26. An impression composition convertible by mixing with water to anelastic gel comprising an alkali metal salt of methplcarboxgcellulose, afluosilicate, lead disilicate, an alkali metal carbonate and a filler.

27. An impression composition convert ble by mixing with water to anelastic gel comprising an alkali metal salt of me'thvlcarborgcellulose,a fluosilicate, lead monosilicate, a filler and an alkali metalcarbonate,

28. An impression composition convertible by mixing with water to anelastic gel comprising i an alkali metal salt of methglcarboxgcellulose,a flnosilicate, lead disilicate, a filler and an alkali metal phosphate.

EDWIN H.

References emu m the file of this patent or the original patent UNITEDSTATES PA-TENTS Number Name Date 2,422,497 Noyes June 17, 1947 2,424,895Noyes July 2a, 1947 2,425,118 Noyes Aug. 5, 1947 Noyes Jan. 8, 1948

